linux-toradex.git/include/linux/pm_domain.h, branch v5.10-rc2 Linux kernel for Apalis and Colibri modules PM: domains: enable domain idle state accounting 2020-10-16T15:53:22+00:00 Lina Iyer ilina@codeaurora.org 2020-10-15T20:47:22+00:00 c6a113b52302adcfadda63af81dc05f7a669fbc8 To enable better debug of PM domains, keep a track of successful and failing attempts to enter each domain idle state. This statistics are exported in debugfs when reading the idle_states node associated with each PM domain. Signed-off-by: Lina Iyer <ilina@codeaurora.org> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
To enable better debug of PM domains, keep a track of successful
and failing attempts to enter each domain idle state.

This statistics are exported in debugfs when reading the
idle_states node associated with each PM domain.

Signed-off-by: Lina Iyer <ilina@codeaurora.org>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: domains: Add support for PM domain on/off notifiers for genpd 2020-10-16T15:39:06+00:00 Ulf Hansson ulf.hansson@linaro.org 2020-10-13T12:23:39+00:00 d4f8138354b9ec290de0c7ba527a945c5549e32b A device may have specific HW constraints that must be obeyed to, before its corresponding PM domain (genpd) can be powered off - and vice verse at power on. These constraints can't be managed through the regular runtime PM based deployment for a device, because the access pattern for it, isn't always request based. In other words, using the runtime PM callbacks to deal with the constraints doesn't work for these cases. For these reasons, let's instead add a PM domain power on/off notification mechanism to genpd. To add/remove a notifier for a device, the device must already have been attached to the genpd, which also means that it needs to be a part of the PM domain topology. To add/remove a notifier, let's introduce two genpd specific functions: - dev_pm_genpd_add|remove_notifier() Note that, to further clarify when genpd power on/off notifiers may be used, one can compare with the existing CPU_CLUSTER_PM_ENTER|EXIT notifiers. In the long run, the genpd power on/off notifiers should be able to replace them, but that requires additional genpd based platform support for the current users. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Lina Iyer <ilina@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
A device may have specific HW constraints that must be obeyed to, before
its corresponding PM domain (genpd) can be powered off - and vice verse at
power on. These constraints can't be managed through the regular runtime PM
based deployment for a device, because the access pattern for it, isn't
always request based. In other words, using the runtime PM callbacks to
deal with the constraints doesn't work for these cases.

For these reasons, let's instead add a PM domain power on/off notification
mechanism to genpd. To add/remove a notifier for a device, the device must
already have been attached to the genpd, which also means that it needs to
be a part of the PM domain topology.

To add/remove a notifier, let's introduce two genpd specific functions:
 - dev_pm_genpd_add|remove_notifier()

Note that, to further clarify when genpd power on/off notifiers may be
used, one can compare with the existing CPU_CLUSTER_PM_ENTER|EXIT
notifiers. In the long run, the genpd power on/off notifiers should be able
to replace them, but that requires additional genpd based platform support
for the current users.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: domains: Rename power state enums for genpd 2020-10-02T17:15:16+00:00 Ulf Hansson ulf.hansson@linaro.org 2020-09-24T11:04:47+00:00 49f618e1b669ef0e26a8d8d7f8fafc7b8fd31531 To clarify the code a bit, let's rename GPD_STATE_ACTIVE into GENPD_STATE_ON and GPD_STATE_POWER_OFF to GENPD_STATE_OFF. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> [ rjw: Subject edit ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
To clarify the code a bit, let's rename GPD_STATE_ACTIVE into
GENPD_STATE_ON and GPD_STATE_POWER_OFF to GENPD_STATE_OFF.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: domains: Restore comment indentation for generic_pm_domain.child_links 2020-07-14T13:14:27+00:00 Geert Uytterhoeven geert+renesas@glider.be 2020-07-14T12:56:25+00:00 afb0367a80553e795e7ad055299096544454f3f6 The rename of generic_pm_domain.slave_links to generic_pm_domain.child_links accidentally dropped the TAB to align the member's comment. Re-add the lost TAB to restore indentation. Fixes: 8d87ae48ced2dffd ("PM: domains: Fix up terminology with parent/child") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> [ rjw: Minor subject edit ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
The rename of generic_pm_domain.slave_links to
generic_pm_domain.child_links accidentally dropped the TAB to align the
member's comment.  Re-add the lost TAB to restore indentation.

Fixes: 8d87ae48ced2dffd ("PM: domains: Fix up terminology with parent/child")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
[ rjw: Minor subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: domains: Fix up terminology with parent/child 2020-07-09T12:24:00+00:00 Kees Cook keescook@chromium.org 2020-07-08T23:32:13+00:00 8d87ae48ced2dffd5e7247d19eb4c88be6f1c6f1 The genpd infrastructure uses the terms master/slave, but such uses have no external exposures (not even in Documentation/driver-api/pm/*) and are not mandated by nor associated with any external specifications. Change the language used through-out to parent/child. There was one possible exception in the debugfs node "pm_genpd/pm_genpd_summary" but its path has no hits outside of the kernel itself when performing a code search[1], and it seems even this single usage has been non-functional since it was introduced due to a typo in the Python ("apend" instead of correct "append"). Fix the typo while we're at it. Link: https://codesearch.debian.net/ # [1] Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
The genpd infrastructure uses the terms master/slave, but such uses have
no external exposures (not even in Documentation/driver-api/pm/*) and are
not mandated by nor associated with any external specifications. Change
the language used through-out to parent/child.

There was one possible exception in the debugfs node
"pm_genpd/pm_genpd_summary" but its path has no hits outside of the
kernel itself when performing a code search[1], and it seems even this
single usage has been non-functional since it was introduced due to a
typo in the Python ("apend" instead of correct "append"). Fix the typo
while we're at it.

Link: https://codesearch.debian.net/ # [1]
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / Domains: Introduce a genpd OF helper that removes a subdomain 2020-01-02T15:52:40+00:00 Ulf Hansson ulf.hansson@linaro.org 2019-12-30T12:59:30+00:00 dedd14925ec6f82a2840c009bc175e2b528ace8e We already have the of_genpd_add_subdomain() helper, but no corresponding of_genpd_remove_subdomain(), so let's add it. Subsequent changes starts to make use of it. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Rafael J. Wysocki <rafael@kernel.org> 
We already have the of_genpd_add_subdomain() helper, but no corresponding
of_genpd_remove_subdomain(), so let's add it. Subsequent changes starts to
make use of it.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
PM / Domains: Introduce dev_pm_domain_start() 2019-11-13T10:41:50+00:00 Ulf Hansson ulf.hansson@linaro.org 2019-10-16T13:16:03+00:00 ca765a8cfe0c78bfa47b9d67121f4e342d4b4512 For a subsystem/driver that either doesn't support runtime PM or makes use of pm_runtime_set_active() during ->probe(), may try to access its device when probing, even if it may not be fully powered on from the PM domain's point of view. This may be the case when the used PM domain is a genpd provider, that implements genpd's ->start|stop() device callbacks. There are cases where the subsystem/driver managed to avoid the above problem, simply by calling pm_runtime_enable() and pm_runtime_get_sync() during ->probe(). However, this approach comes with a drawback, especially if the subsystem/driver implements a ->runtime_resume() callback. More precisely, the subsystem/driver then needs to use a device flag, which is checked in its ->runtime_resume() callback, as to avoid powering on its resources the first time the callback is invoked. This is needed because the subsystem/driver has already powered on the resources for the device, during ->probe() and before it called pm_runtime_get_sync(). In a way to avoid this boilerplate code and the inefficient check for "if (first_time_suspend)" in the ->runtime_resume() callback for these subsystems/drivers, let's introduce and export a dev_pm_domain_start() function, that may be called during ->probe() instead. Moreover, let the dev_pm_domain_start() invoke an optional ->start() callback, added to the struct dev_pm_domain, as to allow a PM domain specific implementation. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
For a subsystem/driver that either doesn't support runtime PM or makes use
of pm_runtime_set_active() during ->probe(), may try to access its device
when probing, even if it may not be fully powered on from the PM domain's
point of view. This may be the case when the used PM domain is a genpd
provider, that implements genpd's ->start|stop() device callbacks.

There are cases where the subsystem/driver managed to avoid the above
problem, simply by calling pm_runtime_enable() and pm_runtime_get_sync()
during ->probe(). However, this approach comes with a drawback, especially
if the subsystem/driver implements a ->runtime_resume() callback.

More precisely, the subsystem/driver then needs to use a device flag, which
is checked in its ->runtime_resume() callback, as to avoid powering on its
resources the first time the callback is invoked. This is needed because
the subsystem/driver has already powered on the resources for the device,
during ->probe() and before it called pm_runtime_get_sync().

In a way to avoid this boilerplate code and the inefficient check for "if
(first_time_suspend)" in the ->runtime_resume() callback for these
subsystems/drivers, let's introduce and export a dev_pm_domain_start()
function, that may be called during ->probe() instead.

Moreover, let the dev_pm_domain_start() invoke an optional ->start()
callback, added to the struct dev_pm_domain, as to allow a PM domain
specific implementation.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / Domains: Align in-parameter names for some genpd functions 2019-08-05T08:58:19+00:00 Ulf Hansson ulf.hansson@linaro.org 2019-07-16T09:43:20+00:00 0d1e16c640ee67dcae65ae8e3c6f58e6d8101047 Align in-parameter names for the declarations of pm_genpd_add| remove_subdomain() and of_genpd_add_subdomain() according to their implementations, as to improve consistency. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Align in-parameter names for the declarations of pm_genpd_add|
remove_subdomain() and of_genpd_add_subdomain() according to their
implementations, as to improve consistency.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05T15:37:16+00:00 Thomas Gleixner tglx@linutronix.de 2019-06-01T08:08:42+00:00 55716d26439f5c4008b0bcb7f17d1f7c0d8fbcfc Based on 1 normalized pattern(s): this file is released under the gplv2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 68 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Based on 1 normalized pattern(s):

  this file is released under the gplv2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 68 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PM / Domains: Add GENPD_FLAG_RPM_ALWAYS_ON flag 2019-05-13T08:51:31+00:00 Leonard Crestez leonard.crestez@nxp.com 2019-04-30T15:06:11+00:00 ed61e18a4b4e445ae8622a4faec6a259601cc4a5 This is for power domains which can only be powered off for suspend but not as part of runtime PM. Suggested-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
This is for power domains which can only be powered off for suspend but
not as part of runtime PM.

Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>